Sample cylinder, especially a sample cylinder that is provided with a filtration device for recovering cell material from body fluids

ABSTRACT

For the purpose of obtaining medical preparations by means of a printing technique, a specimen cylinder ( 1 ) is provided with a syringe cone segment ( 2 ) that can be severed from a cylinder segment ( 2 ), so that preferably after the syringe cone segment has been removed a filtering device ( 6 ) with a filter ( 8 ) which is held so as to be sealed relative to the inner wall ( 7 ) of the specimen cylinder ( 1 ) projects by a surface ( 9 ) axially over its holder ( 5 ) and over the cylindersegment ( 2 ) in an operational position of the filtering device ( 6 ) and can be pressed onto a specimen carrier in a simple manner.

DESCRIPTION

[0001] The invention is directed to a sample cylinder or specimencylinder with a syringe cone segment, particularly with a filteringdevice for recovering cell material from body fluids.

[0002] A filtering device for separating and collecting cells andparticles from liquids is known from DE 3719302. Efficiency can beincreased through the use of this device, particularly in quantitativeevaluation methods, e.g., in urine sediment analysis. The devicedescribed in the above-cited reference has a specimen cylinder with asyringe cone segment. A filtration tube which is displaceable in themanner of a syringe plunger and has a one-stage or two-stage filterdevice at one end is inserted into the specimen vessel.

[0003] Diagnostic chores, e.g., in the field of urine analysis, requirethat the particles occurring in urine, such as erythrocytes, leukocytes,urothelial cells, other accompanying cells, crystalline bodies, hyalinecylinders and germs are concentrated and accumulated from a largequantity of liquid, e.g., from a full bladder or from 50 -ml or 100 -mlsamples, without losses in a sediment or in a constant 1 -ml amount ofliquid. This allows the filtering device to separate and collect cellsand particles from liquids, e.g., from urine. Qualitative evaluation iscarried out in a manner known per se by adding the specimen by drops tocell counters.

[0004] In connection with improved diagnostic possibilities, the knowndevice was improved for cytological purposes where the cell material onmicroscope slides should have a perfect morphology. To this end, afiltration tube in a known device is guided inside a specimen cylinderwith a syringe cone segment and adjoining cylinder segment so as to besealed against the cylindrical inner wall of the specimen cylinder. Whena liquid is drawn in the manner of a syringe and received in thespecimen cylinder, and the syringe cone is closed or the specimencylinder, with the filtration tube removed, is filled with body fluidand then the filtration tube is inserted, the specimen liquid passesthrough the filtering device when the filtration tube is pressed downagainst the specimen liquid and collects in the filtration tube orpasses out in some other manner.

[0005] During the filtration process, additional particles collect on afilter surface which projects particularly over the filtering device.The filtration tube is then usually removed from the specimen cylinderafter the specimen liquid has been withdrawn. The particles which havecollected on the filter surface can then be transferred to a slide,e.g., for microscopic diagnosis, so that an accumulated suspension inthe specimen cylinder which is needed for quantitative analysis isdispensed with.

[0006] This print technique has proven extremely successful forobtaining medical preparations. However, in order to transfer the cellmaterial that has collected on the filter surface to slides by this kindof printing, the filtration tube must be removed from the specimencylinder. For this purpose, after the filtrate or residue has beenremoved, the device which is now open is turned over and set on acellulose base, for example. The specimen cylinder can then be pulledout of the filtration tube against considerable resistance through theuse of corresponding force. In so doing, remainders of the specimen willinevitably flow down the outer wall and can wet the user's fingers aswell as the base. This risk of contamination, for example, in case ofinfectious material, is disadvantageous and is not tolerable for reasonsof hygiene.

[0007] Precisely in view of such a risk of contamination, reuse ofdevices that have already been used should also be ruled out.

[0008] This set of technical problems is solved generally in a specimencylinder with a syringe cone segment by the specimen cylinder accordingto the invention, wherein, according to claim 1, the syringe conesegment can be separated from a cylinder segment. In particular, theidea consists in that in a specimen cylinder having a filtering devicewith a filter which is held so as to be sealed relative to the innerwall of the specimen cylinder, a surface of the filter projects axiallyover its holder and over the cylinder segment in an operational positionof the filtering device when the syringe cone segment is removed.

[0009] The steps undertaken in the specimen cylinder according to theinvention achieve a number of advantages. When the filtering device isinserted into the specimen cylinder in the manner of a filtering tube,it no longer needs to be removed from the specimen cylinder. Rather, thefilter surface with the collected cell contents and particles is freelyaccessible after the syringe cone segment is removed, for example, fortransferring these cell contents and particles onto a microscope slideor specimen carrier. For this purpose, the surface advisably projectsaxially over the holder of the filter as well as over the cylindersegment in this operational position and is accordingly freelyaccessible.

[0010] Consequently, the cell material that has collected on the surfaceof the filter comes into contact with the environment when and only whenit also undergoes further preparation. In particular, an unintentionaldrying out of the filter outside of the specimen cylinder is alsoimpossible. Rather, the filter surface with the cell material remains inthe microclimate of the specimen cylinder until the above-mentionedpreparation step. Also, a mechanical influence on the cell contents onthe filter surface, e.g., due to tilting of the filtering device duringremoval, striking against the free edge of the specimen cylinder or thelike, is reliably prevented by the steps according to the invention.

[0011] In a preferred construction, the cylinder segment and a portionof the syringe cone segment form a common cylindrical inner wall of thespecimen cylinder. The syringe cone is accordingly completely severedfrom the cylinder segment, i.e., separation is effected in an areahaving a constant, cylindrical cross section and not in the area of thesyringe cone tapering toward the free end. As a result of this step, themaximum cross section of the specimen cylinder is available at theseparation point after the syringe cone segment is severed. Further, theaxial movability of the inserted filtering device can not be impaired inany way by this step. Moreover, the tightness of the holder relative tothe inner wall of the specimen cylinder is ensured, even up to theseparating point, because there is no change in cross section in theinner wall.

[0012] In a first alternative design, the cylinder segment and syringecone segment are constructed in two pieces. Suitable steps must then betaken to connect the syringe cone segment to the cylinder segment so asto be tight against liquid.

[0013] When an axially stationary filtering device is desired, theholder of the filter can connect the cylinder segment and syringe conesegment to one another. A connection of this kind can be provided in amanner known per se by suitable snap-in connections, catch connectionsand screw connections. Sealing rings which guarantee a liquid-tightconnection can be provided in addition.

[0014] However, since axial movability of the filtering device isusually necessary for the tasks mentioned in the beginning, the cylindersegment and syringe cone segment are advisably connected to one anotherby an outer and/or inner sleeve. With respect to an outer sleeve, thecylinder segment and syringe cone segment advisably have the same outerand preferably the same inner diameter at least in the area of theseparation point. For an inner sleeve, identical inner diameters arealso usually required. When the inner sleeve extends over the entirecylindrical area of the specimen cylinder, there is also no problem withsealing relative to the holder for the filter. Alternatively, a frontside of an inner sleeve of this type can form a deliberate axial stopfor the filtering device, e.g., for fixing an exact volume of thesyringe cone segment.

[0015] Also, different inner diameters of the cylinder segment andsyringe cone segment can be compensated by an inner sleeve with astepped or graduated outer diameter and an inner diameter can be madeavailable specifically for filtering devices that are adapted forspecial tasks.

[0016] It is possible to construct the sleeves separately.Alternatively, a sleeve of this type can also be constructed integralwith the cylinder segment and/or with the syringe cone segment such thatthe cylinder segment and syringe cone segment are connected so as tooverlap axially. In individual cases, a telescoping insertion of thecylinder segment and syringe cone segment may also be adequate as aconnection.

[0017] Besides the two-piece constructional variant, the cylindersegment and syringe cone segment can also be constructed in one pieceand can be separable at a predetermined breaking point. In this variantalso, separation is possible in a well-defined manner by means of thepredetermined breaking point. A predetermined breaking point of thiskind is usually formed at this location by a narrowing of the crosssection and, if required, can be mechanically reinforced by ribs whichbreak or tear in a suitable manner.

[0018] Regardless of whether a one-piece or two-piece construction iscarried out, it is provided in a further development that the connectionof the syringe cone segment to the cylinder segment is carried out inthe manner of a safety lock or tamperproof closure such as is known inthe art, e.g., for bottles. This step makes it possible to detect usedequipment in a reliable manner regardless of whether or not the specimencylinder according to the invention can regularly be separated intocylinder segment and syringe cone segment and then assembled again.

[0019] In exceptional cases, particularly for applications requiringhighly sterile conditions, the latter feature is usually undesirable. Inthat case, it is provided that when the connection elements and/orsealing elements or the syringe cone segment itself are destroyed whenthe syringe cone segment is severed from the cylinder segment, they cannot be put together again so as to be operational.

[0020] It can be provided particularly in the two-piece construction ofthe specimen cylinder according to the invention that the specimencylinder has an axial stop for the filtering device in the area of theseparation point of the syringe cone segment and cylinder segment. Inparticular, the severed edges of the syringe cone segment and cylindersegment can have, as a stop, a projection which faces inward andprojects over the inner wall. This step also ensures that a defined,predeterminable volume is available on the syringe cone side.

[0021] The invention will be described more fully with reference to thedrawings which show embodiment examples only.

[0022]FIG. 1 is a sectional view showing a specimen cylinder withinserted filtering device according to the invention;

[0023]FIG. 2 shows the specimen cylinder according to FIG. 1 without thesyringe cone segment;

[0024]FIG. 3 shows a second embodiment example in section in the area ofthe separation point;

[0025]FIG. 4 shows a third embodiment example;

[0026]FIG. 5 shows a fourth embodiment example; and

[0027]FIG. 6 shows a fifth embodiment example.

[0028]FIG. 1 shows a specimen cylinder 1, according to the invention,comprising a cylinder segment 2 and a separable syringe cone segment 3which are constructed in two pieces in the embodiment example shown inFIGS. 1 and 2. The syringe cone segment 3 which is closed by a cap 4 isconnected to the cylinder segment 2 by a holder 5 of a filtering device6, shown in a simplified manner, which is inserted into the specimencylinder 1 and which is also already known, e.g., from DE 3719302. Theholder 5 holds a filter 8 by a portion 11 so as to be sealed relative tothe inner wall 7 of the specimen cylinder 1. The filter 8 projectsaxially over the holder 5 by a surface 9. This projecting portion has amushroom-like appearance owing to a radial necking down of the filter 8due to the holder 5, e.g., due to a conical filter receptacle and acircumferential projection which faces radially inward.

[0029] The cylinder segment 2 and a portion 10 of the syringe conesegment 3 together form the cylindrical inner wall 7 of the specimencylinder 1. Consequently, the holder 5 can join the cylinder segment 2and the syringe cone segment 3 together by portion 11 which has aconstant cross section formed by the dimensioning of the innercylindrical area of the specimen cylinder 1.

[0030] Depending on the construction, this connection can be carried outby means of a simple press fit and/or clamping fit of the cylindersegment 2 and syringe cone segment 3 on portion 11 of the holder 5.Catch closures, snap-in closures or screw closures, not shown inparticular, are all equally possible without difficulty. Further,sealing elements such as sealing rings 14 can be inserted in portion 11in addition. These steps are essentially determined by the intended useof the specimen cylinder 1 according to the invention.

[0031] In the embodiment form shown in FIGS. 1 and 2, the filteringdevice 6 is not inherently axially displaceable in the specimen cylinder1. Nevertheless, a liquid specimen can easily be sucked in by drawingout the tube 15. Alternatively, for example, a suction pump, a balloon17 of sufficient size, or the like, can be fitted to the free end 13 ofthe specimen cylinder 1. As a result of the liquid flowing through thefilter 8 in the direction indicated by the arrow 12, cell material thatis filtered out is deposited on the surface 9 of the filter 8.

[0032] After the collected liquid has been removed, possibly afterremoving the cap 4, including the liquid collected in the syringe conesegment 3, the syringe cone segment 3 can be severed from the cylindersegment 2, according to the invention, in the plane 17 indicated by adash-dot lone in FIG. 1. In the operational position of the filteringdevice 6 according to FIG. 2, the surface 9 then projects freely axiallyover the cylinder segment 2 and the holder 5.

[0033] In this embodiment example, the cylinder segment 2 and the holder5 of the filtering device 6 can be nondetachably connected and, ifnecessary, can even be constructed so as to form one piece.

[0034] In order to place a medical preparation on a microscope slide orspecimen carrier 16, the cylinder segment 2 with the filtering device 6is carefully placed by its surface 9 on the specimen carrier verticallyas indicated by arrow 18 in FIG. 2 in order to transfer the cellmaterial located on the surface 9 to the specimen carrier 16.

[0035] When a cylindrical portion 25 of the syringe cone segment 24 andthe cylinder segment 23 have the same inner cross section as is shown inFIG. 3, a common inner wall 26 of the specimen cylinder 20 is formed.Accordingly, the filtering device 27 can move freely axially. A tube 30which is guided within the specimen cylinder 20 and sealed relative tothe latter forms a holder 28 of the filter 29 at the same time. Then aspecimen liquid which is drawn in when the cap 33 is attached collectsin the tube 30.

[0036] When a filtering process is concluded, the filtrate located inthe tube 30 can be poured off, according to the prior art, the tube 30can be removed from the specimen cylinder 20 in the manner describedabove, and the cell material located on the filter surface 31 can betransferred to a specimen carrier. Filtrate still remaining in the tubecan serve as a backwash medium if required.

[0037] However, in the specimen cylinder according to the invention, thetube 30 is restored to the position shown in FIG. 3 after the filtratehas been poured off, and the filter surface 24 projects axially over theholder 28 of the filter 29 and over the cylinder segment 23 after thesyringe cone segment 24 has been removed for transferring the filteredout cell material to a specimen carrier.

[0038] For this purpose, in the two-piece embodiment form of thespecimen cylinder 20 according to FIG. 3, an outer sleeve 21 overlaps aseparation 22, shown in an enlarged view, between the cylinder segment23 and the syringe cone segment 24.

[0039] In a simple embodiment form, the outer sleeve 21 which isconstructed as a shrink tubing, for example, can connect the cylindersegment 23 to the syringe cone segment 24. However, solidly constructedsleeves 21 which are formed in such a way that the syringe cone segment24 and the cylinder segment 23 are connected with the sleeve 21 by meansof a catch connection, a snap connection or screw connection, possiblyincluding suitable sealing elements, are preferable.

[0040] Further, separately constructed sealing rings 32 are additionallyprovided so that the holder 28 for the filter 29 of the filtering device27 is well-sealed relative to the inner wall 26.

[0041] In the specimen cylinder 35 according to FIG. 4, which is also atwo-part construction, the syringe cone segment 36 is constructed in themanner of a cap so as to axially overlap and engage over the cylindersegment 37. It can be ensured by means of suitable graduation (see arrow38) that a portion of the cylinder segment 36 and the cylinder segment37 form a common cylindrical inner wall 39. Due to this step, thefiltering device 40 is again freely movable axially within the specimencylinder 35.

[0042] Arrow 41 indicates the connection elements and/or sealingelements which ensure the liquid-tight connection of the syringe conesegment 36 to the cylinder segment 37. For example, these elements canbe inserted sealing rings, suitably constructed projections and recesseswhich catch or snap together, a thread, or the like.

[0043] When it must be ensured in particular that the specimen cylinderaccording to the invention can not be reused, these connection elementsand/or sealing elements 41 are advisably destroyed when the syringe conesegment 36 is detached from the cylinder segment 37 in such a way thatit is no longer possible to reassemble them so as to be operational.

[0044] Accordingly, a connection between the syringe cone segment 36 andthe cylinder segment 37 is constructed in the manner of a tamperproofclosure which allows reliable detection of tampering.

[0045] In addition to the two-piece construction of the specimencylinder according to the invention, it is also possible to construct aspecimen cylinder 45 in one piece in a simple manner with respect tomanufacturing technique. The cylinder segment 46 and syringe conesegment 47 can then be separated in a regular manner at a predeterminedbreaking point 48 with a clearly defined area of separation. Apredetermined breaking point 48 of this kind usually has a cross sectionwhich is small enough to enable the cylinder segment 45 and syringe conesegment 47 to be separated easily by tearing or breaking thepredetermined breaking point 48. In order to ensure sufficientmechanical stability, reinforcing ribs 49, which are also provided withpredetermined breaking points themselves if need be, can furtherstrengthen the mechanically weak connection along the predeterminedbreaking point 48.

[0046] In a one-part construction of this kind, the specimen cylinder 45can also be designed so as to be reusable. Alternatively, it is alsopossible in this case to exclude reuse by appropriate tearing orbreaking of the predetermined breaking point 48 and/or ribs 49. In everycase, in a one-piece construction of the specimen cylinder 45 of thistype, it can easily be seen whether or not it has already been used.

[0047]FIG. 6 shows another two-part construction of a specimen cylinder50 with a cylinder segment 51 and a syringe cone segment 52. In thetwo-part embodiment form shown in FIG. 6, it is possible to provide theends of the cylinder segment 51 and syringe cone segment 52 that faceone another with a projection 53 which faces radially inward.

[0048] When projections of the type mentioned above are provided at thesyringe cone segment 52 as well as at the cylinder segment 51, they canalso be used as a connection element and/or sealing element. Inparticular, a projection 53 of this kind which projects inward alsoforms an axial stop for the filtering device 54. Accordingly, an exactlydefined volume can be predetermined inside the syringe cone segment 52in the operational position of the filtering device 54 according to FIG.6. When the wall of the cylindrical portion of the syringe cone segment52 is constructed with a suitable thickness, its front side can alsoform the stop for the filtering device 54 without the need for aprojection 53 projecting over the inner wall.

[0049] Further, FIG. 6 shows a radially circumferential, axiallyprojecting lip 55 at the end of the cylinder segment 50 facing thesyringe cone segment 52. This lip 55 is held in a sealing manner in acorresponding recess of the syringe cone segment 52. In this case, also,the abovementioned steps for additional sealing and for a secure holdcan again be provided in the form of sealing elements, snap-in and catchconnections, threads, etc.

1. Specimen cylinder with a syringe cone segment, characterized in thatthe syringe cone segment (3) can be separated from a cylinder segment(2).
 2. Specimen cylinder according to claim 1, having a filteringdevice (6) with a filter (8) which is held so as to be sealed relativeto the inner wall (7) of the specimen cylinder (1), a surface (9) of thefilter (8) projecting axially over its holder (5) and over the cylindersegment (2) in an operational position of the filtering device (6) afterthe syringe cone segment (3) has been severed.
 3. Specimen cylinderaccording to one or more of the preceding claims, characterized in thatthe cylinder segment (2) and a portion (10) of the syringe cone segment(3) form a common cylindrical inner wall (7) of the specimen cylinder(1).
 4. Specimen cylinder according to one or more of the precedingclaims, characterized in that the cylinder segment (2) and syringe conesegment (3) are constructed in two pieces.
 5. Specimen cylinderaccording to one or more of the preceding claims, characterized in thatthe cylinder segment (2) and the syringe cone segment (3) are connectedto one another by the holder (5) of the filter (8).
 6. Specimen cylinderaccording to one or more of the preceding claims, characterized in thatthe cylinder segment (23) and syringe cone segment (24) are connected toone another by an outer and/or inner sleeve (21).
 7. Specimen cylinderaccording to one or more of the preceding claims, characterized in thatthe cylinder segment (37) and syringe cone segment (36) are connected toone another so as to overlap axially.
 8. Specimen cylinder according toone or more of the preceding claims, characterized in that the cylindersegment (3) and syringe cone segment (2) can be separated in anondestructive manner.
 9. Specimen cylinder according to one or more ofthe preceding claims, characterized in that the cylinder segment (45)and syringe cone segment (47) are constructed in one piece and areseparable at a predetermined breaking point (48).
 10. Specimen cylinderaccording to one or more of the preceding claims, characterized in thatthe connection of the syringe cone segment (36) to the cylinder segment(37) is formed in the manner of a tamperproof closure.
 11. Specimencylinder according to one or more of the preceding claims, characterizedby the destruction of the connection elements and/or sealing elements(41) and of the syringe cone segment when the syringe cone segment (36)is severed from the cylinder segment (37).
 12. Specimen cylinderaccording to one or more of the preceding claims, characterized in thatthe specimen cylinder (50) has an axial stop (53) for the filteringdevice (54) in the area of the separation point of the syringe conesegment (52) and cylinder segment (51).